Answer : It is dependent on the designer's rates and the scope of the project. Usually, interior designers charge an hourly rate, or they may charge a flat fee for a particular project.
One way to get an estimate for the cost of hiring an interior designer is to measure the square footage of the space that needs to be designed and then multiply that by the designer's hourly rate. So for example, if you have a 1,000 square foot home and you want to hire an interior designer who charges $100 per hour, then your total cost would be $10,000.
Another thing to consider is whether or not you will need furniture or other decorating accessories designed by the interior designer.